One-Piece Chair Backs and Chairs Having the Same

ABSTRACT

A chair has a chair back including a frame, two supporting legs and a bearing plate. The frame is integrated to the supporting legs in an injection molding manner. The bearing plate is integrated to a bottom frame portion and two side frame portions of the frame in the injection molding manner so that a user can lean against the bearing plate. The two side frame portions are located on two opposite sides of the bottom frame portion. The hardness of the bearing plate is lower than the hardness of the frame, and the hardness of the frame is lower than the hardness of the supporting leg. Therefore, two members whose materials are different in hardness are possibly constitute a chair back formed in one piece.

BACKGROUND Field of the Invention

The present invention relates to chair backs, and more particularly to one-piece chair backs and chairs having the same.

Description of Related Art

Most of the existing one-piece chair backs are made of a single material through injection molding. However, in order to maintain good support for such a chair back, the material selected is usually stiffer and less elastic and ductile, resulting in some sacrifice of the user's comfort when leaning against the chair back.

Therefore, how to manufacture the chair back from materials with different hardness and softness is an issue to be overcome at present.

SUMMARY

One objective of the present invention is to provide an one-piece chair back and a chair having the same, whereby the chair back can have at least two components with different harnesses through the manufacturing process design, the selection of materials and the formulating of material ratio.

Another objective of the present invention is to provide an one-piece chair back and a chair having the same, whereby the chair back uses a frame made of relatively harder material to support a softer (or tougher) bearing plate that is used for a user to rest against.

An one-piece chair back according to an embodiment of the invention includes: a frame including a bottom frame portion and two side frame portions respectively connected to two opposite sides of the chair back, and an accommodating space formed by the bottom frame portion and the two side frame portions; two supporting legs connected to the frame by means of injection molding, and a hardness of the two supporting legs being higher than that of the frame; and a bearing plate disposed in the accommodating space and connected to the two side frame portions and the bottom frame portion by means of injection molding, the bearing plate being configured for a user to rest against, and the bearing plate having a hardness lower than that of the frame.

In some embodiments, the frame and the supporting legs are made of the same material but in different proportions.

In some embodiments, a material of the frame includes nylon and glass fiber, and a content of the glass fiber is 7-30 weight percent.

In some embodiments, a material of each of the supporting legs includes nylon and glass fiber, and a content of the glass fiber is 7-50 weight percent.

In some embodiments, a material of the bearing plate is nylon or polyether-based thermoplastic polyurethane.

In some embodiments, each of the side frame portions is provided with an extension portion facing a first inner side surface of the bearing plate, the extension portions extend in opposite directions, and each of two opposite second inner side surfaces of the bearing plate facing the side frame portions includes an indentation, the indentations are aligned with the extension portions, and positions of the extension portions and the indentations correspond to a position of the user's lower back.

In some embodiments, the extension portions each include at least one first ventilation hole.

In some embodiments, the bearing plate includes at least one second ventilation hole.

In some embodiments, a fixing groove for insertion of a seat is recessed on an end surface of each of the supporting legs at one end thereof away from the frame.

In addition, the invention also provides a chair in accordance with an embodiment, and the chair includes the chair back as mentioned above, and a seat connected to the supporting legs of the chair back.

BRIEF DESCRIPTION OF THE DRAWINGS

After studying the detailed description in conjunction with the following drawings, other aspects and advantages of the present invention will be discovered:

FIG. 1 is an illustrative view of a chair back according to an embodiment of the present invention; and

FIG. 2 is an illustrative view of a chair according to an embodiment of the present invention.

DETAILED DESCRIPTION

In the following detailed description, many specific details are explained in order to provide a thorough understanding of the present invention. However, those of ordinary skill in the art will understand that the present invention can be practiced without these specific details. In other cases, well-known methods, procedures and/or elements have not been described in detail so as not to obscure the present invention.

Please refer to FIGS. 1 and 2 , a chair back 1 according to an embodiment of the present invention is suitable for being assembled to a seat 2 to form a chair 3. The chair back 1 includes a frame 10, two supporting legs 20 and a bearing plate 30.

The frame 10 is formed as one piece and may include two side frame portions 11 and a bottom frame portion 12. The two side frame portions 11 are respectively located on two opposite sides of the chair back 1 and two opposite ends of the bottom frame portion 12. The two opposite ends of the bottom frame portion 12 are respectively connected to the two side frame portions 11. The two side frame portions 11 and the bottom frame portion 12 together form an accommodating space S. The material of the frame 10 may, for example but not be limited to, include nylon (such as but not limited to PA66) and glass fiber, and the content of the glass fiber of the frame 10 is 7 to 30 weight percent, such as but not limited to 10, 16, 20, 24 or 28 weight percent.

The two supporting legs 20 are formed by means of injection molding while be joined to the frame 10 in the process of injection molding. Specifically, the two supporting legs 20 are also located on two opposite sides of the chair back 1 respectively, and each supporting leg 20 is formed at the junction of the side frame portion 11 on the same side and the bottom frame portion 12. A fixing groove 21 is recessed on an end surface of each supporting leg 20 at one end thereof away from the frame 10, and the fixing grooves 21 are used for insertion of plugs P of the seat 2. The hardness of these supporting legs 20 is higher than that of the frame 10. The material of the supporting legs 20 includes nylon (such as but not limited to PA66) and glass fiber, and the content of the glass fiber of the supporting legs 20 is 7-50 weight percent, such as but not limited to 20, 30, 35, 40 or 45 weight percent. Therefore, these supporting legs 20 are configured to support the entire chair back 1 and are detachably assembled to the seat 2. The combination of 30 wt. % glass fiber in 70 wt. % nylon is conducive to making the supporting leg have better chemical properties, dimensional stability, heat resistance and aging resistance, and even making its fatigue resistance increased by as much as 2.5 times as compared to the supporting legs that do not contain glass fibers. The higher the glass fiber content of the supporting leg, the higher the hardness of the supporting leg.

The bearing plate 30 is formed as one piece by means of injection molding while being joined to the two side frame portions 11 and the bottom frame portion 12 of the frame 10 in the process of injection molding, and the bearing plate 30 is located in the accommodating space S. Specifically, the bearing plate 30 includes two opposite second inner side surfaces 31 and a second inner bottom surface 32 connected to the two second inner side surfaces 31. The two second inner side surfaces 31 of the bearing plate 30 are respectively connected to two first inner side surfaces 13 of the side frame portions 11 of the frame 10. The second inner bottom surface 32 of the bearing plate 30 is connected to a first inner bottom surface 14 of the bottom frame portion 12 of the frame 10. The first inner bottom surface 14 of the bottom frame portion 12 is connected to the two first inner side surfaces 13 of the side frame portions 11. Therefore, the bearing plate 30 can be supported by the frame 10 for a user's back to lean against. Compared with the material properties of the frame 10, the bearing plate 30 can be made of materials with lower hardness but higher tensile strength and elasticity, such as but not limited to nylon (such as but not limited to PA66), polyether-based thermoplastic polyurethane or a combination thereof. In this way, when the user's body rests on the bearing plate 30, the bearing plate 30 is capable of being slightly deformed due to the body's pressing, so as to slightly enwrap the user's back, thereby not only supporting the user's back, but also providing proper cushioning effect. This is conducive to achieving the ergonomic design and increasing the comfort to the user sitting on the chair.

In addition, in this embodiment or some embodiments, an extension portion 15 may be extended from the first inner side surface 13 of each of the side frame portions 11. These extension portions 15 extend in opposite directions. An indentation 33 is provided on each of the two second inner side surfaces 31 of the bearing plate 30. The two indentations 33 are aligned with to the two extension portions 15 respectively. Since the hardness of the extension portion 15 is higher than that of the surrounding bearing plate 30, and the positions of the two extension portions 15 correspond to the positions on two sides of the user's lower back, the supporting effect on the user's lower back can be enhanced.

In this embodiment or some embodiments, at least one of the side frame portions 11 may be provided with at least one first ventilation hole 16. For example, the extension portions 15 of the side frame portions 11 each include a plurality of first ventilation holes 16. Therefore, the air permeability of the chair back 1 at the lower back can be enhanced.

In this embodiment or some embodiments, the bearing plate 30 may be provided with a mesh structure or a lattice or grid structure, and the mesh structure includes a plurality of second ventilation holes 34. Through this mesh structure, the bearing plate 30 can be made more elastic and cushioning. The second ventilation holes 34 of the mesh structure are distributed at positions corresponding to the upper and lower backs, on the chair back 1, so that the ventilation of the chair back 1 for the upper and lower backs can be increased. However, the present invention is not limited to this implementation. In another embodiment, the bearing plate 30 can also be changed to have only one second ventilation hole 34.

Although the two supporting legs 20 of the above embodiments are each provided with a fixing groove 21 for a corresponding plug P of the seat 2 to be inserted thereto, the present invention is not limited to this implementation. In other embodiments, the two supporting legs 20 can also be changed into inserts or plugs, so as to be inserted into two fixing grooves of the seat 2.

Although the present invention is disclosed in the foregoing embodiments, these embodiments are not intended to limit the present invention. Changes, modifications, and combinations of implementations made without departing from the spirit and scope of the present invention all belong to the scope of the claims of the present invention. For the protection scope defined by the present invention, please refer to the attached claims. 

What is claimed is:
 1. An one-piece chair back comprising: a frame including a bottom frame portion and two side frame portions respectively connected to two opposite sides of the chair back, and an accommodating space formed by the bottom frame portion and the two side frame portions; two supporting legs connected to the frame by means of injection molding, and a hardness of the two supporting legs being higher than that of the frame; and a bearing plate disposed in the accommodating space and connected to the two side frame portions and the bottom frame portion by means of injection molding, the bearing plate being configured for a user to rest against, and the bearing plate having a hardness lower than that of the frame.
 2. The one-piece chair back as claimed in claim 1, wherein the frame and the supporting legs are made of the same material but in different proportions.
 3. The one-piece chair back as claimed in claim 1, wherein a material of the frame includes nylon and glass fiber, and a content of the glass fiber is 7-30 weight percent.
 4. The one-piece chair back as claimed in claim 1, wherein a material of each of the supporting legs includes nylon and glass fiber, and a content of the glass fiber is 7-50 weight percent.
 5. The one-piece chair back as claimed in claim 1, wherein a material of the bearing plate is nylon or polyether-based thermoplastic polyurethane.
 6. The one-piece chair back as claimed in claim 1, wherein each of the side frame portions is provided with an extension portion facing a first inner side surface of the bearing plate, the extension portions extend in opposite directions, and each of two opposite second inner side surfaces of the bearing plate facing the side frame portions includes an indentation, the indentations are aligned with the extension portions, and positions of the extension portions and the indentations correspond to a position of the user's lower back.
 7. The one-piece chair back as claimed in claim 6, wherein the extension portions each include at least one first ventilation hole.
 8. The one-piece chair back as claimed in claim 1, wherein the bearing plate includes at least one second ventilation hole.
 9. The one-piece chair back as claimed in claim 1, wherein a fixing groove for insertion of a seat is recessed on an end surface of each of the supporting legs at one end thereof away from the frame.
 10. A chair, comprising the chair back as claimed in claim 1, and a seat connected to the supporting legs of the chair back. 